Roller assembly suspension structure



Oct. 15, 1963 R. F. Lo PRES-r1 ROLLER ASSEMBLY SUSPENSION STRUCTURE 2 Sheets-Sheet 1v Filed May 27, 1959 .fd r .H Lm E m ,m SNL E044 .Sw E@ @a M r.. .w C W NW L. IL r r /N QSN\ N Mf .M l f NQN w N T NNN SNN @NSR .--li n :Nc SKL m\ NN h l L Tlv www w m\w\% 8/ m mfx QN EL N LS EN S .BN C SSN QN .N.m Jr

Oct. 15, 1963 R. F. 1.o PREsTx 3,107,003

ROLLER ASSEMBLY SUSPENSION STRUCTURE Filed Maly 27, 1959 2 SheebSSheel. 2

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Ddl/fer 6a/#far 3,107,003 ROLLER ASSEMBLY SUSPENSION STRUCTURE Roy F. Lo Presti, Chicago, Ill., assigner to Goodman Manufacturing Company, Chicago, Ill., a corporation of Illinois Filed May 27, 1959, Ser. No. 816,227 1 Claim. (CI. 198--192) This invention relates to an improvement in ilexible strand conveyors of the type illustrated in the Craggs and McCann patent, 2,773,257.

In this type of conveyor, a pair of generally parallel flexible strands are trained along a mine run and supported at intervals by strands or other supporting means. A plurality of troughing idler assemblies generally composed of three or more interconnected rollers are hung from the strands at spaced intervals to form a bed for the conveying reach of a load carrying flexible conveyor belt` A plurality of return rollers are also spaced along the conveyor. These return rollers may be built into the strands, carried by independent supporting structures or suspended from the flexible strands. Generally they are spaced at greater intervals than the load carrying troughing idler assemblies because their primary function is merely to support the belt.

One great advantage of supporting the return rollers from the strands is that belt drift can be -more easily controlled. As the belt passes over the rollers, it occasionally tends to drift or detrain from side to side due to a variety of factors, such as roller misalignment. This detraining effect is undesirable because it increases the power consumption necessary to run the belt and, if the detraining is too extreme, frays the edges of the belt against the exible strand support structures or other projections adjacent the conveyor. By suspending the return rollers in pendlum fashion from the strands, an inherent horizontal canting or training movement is imparted to the return rollers by the belt, which tends to steer the belt back towards a centered position. Similarly, a vertical tilting motion can be imparted to the belt in opposition to belt drift which also tends to center the belt along the roller assemblies.

One very feasible method of suspending the return rollers utilizes chain links secured at *their upper ends to the exible strands and at their lower ends to the rollers. This mode of suspension is most effective when the chains converge inwardly upwardly towards the strands. This however requires that the rollers, or at least the roller shafts, be extended outwardly beyond their required operational length. This increased length is undesirable in mines in which clearance along the sides of the conveyor is at a minimum because it hinders movement of men and machines along the mine and increases the cost of the return roller assemblies.

Accordingly, a primary object of the invention is to provide a freely suspended return roller which exerts a training effect on the belt without increasing the length of the roller.

Another object is to stabilize a return roller assembly of a flexible strand conveyor by minimizing the drift of the assembly.

Another object is to minimize drift of a flexibly suspended return roller assembly while maintaining the training effect of the assembly without using return roller shaft extensions.

3, l 7,0013 Patented Get. l5, 1963 .fe Y i@ Another object is a provide a return roller assembly including a return roller having generally vertical upright members connected to its ends which in turn lare swivelably connected to second members in turn swivelably connected to support means such as the ilexible strands.

Other objects and advantages of the invention will become apparent from the following description taken in connection lwith the accompanying drawings wherein by way of illustration and example certain embodiments of the invention are set forth.

The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:

FIGURE l is a side elevation of a flexible strand conveyor;

FIGURE 2 is a section taken along the line 2--2 of FIGURE 1;

FIGURE 3 is a view taken on the line 3 3 of FIG- URE 2 FIGURE 4 is a partial plan view taken along the line 4-4 of FIGURE 2; and

FIGURE 5 is a view similar to FIGURE 2 illustrating another embodiment of the invention.

Like reference numerals will be used to refer to like parts throughout the specification and drawings.

yIn FIGURE l a flexible strand conveyor of the type illustrated in the Craggs and McCann patent is illustrated generally at 200. The conveyor rests on a mine tloor 201 and includes a belt having an upper load carrying conveying reach 202 and a lower return reach 203. The upper conveying reach is supported by a plurality of troughing idler assemblies 204 suspende-d at generally equally spaced intervals along flexible strands 205, 206 which in turn are supported by stands 207, 20S. 'Ilhe return reach of the belt is supported at intervals by return roller assemblies indicated generally at 209.

In 'FIGURE 2 the support strands 207 and 298 are shown as including telescoping upper and lower portions .210 and 211 `which may be set at any desired height by suitable adjusting means, not shown. The lower telescoping member 211 is secured to a foot or base 212 resting on the ground 201. Ushaped saddle members 213 are welded or otherwise suitably secured to the upper ends of each of the upper telescoping members to form a seat for the flexible strands 205 and 206. The strands are maintained a flixed distance apart by a spacer strut 214.

The upper load carrying reach 202 of a llexible conveyor belt is trained along a troughing idler assembly 204 which in this instance is shown as comprising a center primary load carrying roller v215 pivotally connected as at 216 and 217 to a piair of diinking end or wing rollers 21S and 219. The wing rollers in turn are connected by links 220 and 221 to connector hooks 222, 223 engaging the flexible strands. The mode of connecting the hooks to the strands is not per se illustrated since it `does not form an integral part of the invention.

vThe return roller assembly 209 which supports the return reach 203 of the belt includes an elongated return roller 224 rotating on a dead shaft 225. The projecting ends of the shaft are received in a pair of hubs 226, 227 which are welded to upwardly projecting strap members 228, 229. The shaft 22S may rotate freely in the hub or be fixed to it as by pins 230, but in any event Vthe `shaft and strap are restrained from ilexing in either a vertical or horizontal direction. Chains 231, 232 connect the strap and return roller to the flexible strands. The lower ends of the chains are received in apertures 233 in the end plate or straps, as shown best in FIGURE 3, 4and the upper ends are connected to invented U-shapedV hooks 234 which hang from the strands. Suitable wedges 235 force the strand into snug seating engagement with the suspending hooks. Ihe end plates, chains and hooks form in effect an elongated connector which freely suspends the return roller from the strands.

In FIGURE 4 the direction of belt travel is indicated by arrow 236 and the axis of roller 224, when positioned transversely to the direction of belt travel, is indicated at 237.

Another embodiment of the invention is illustrated in FIGURE 5. In this instance the troughing idler assembly has been omitted for purposes of clarity. The return reach 203 is carried by return roller 224 rotating on dead shaft 225 as before. The shaft is received in stub end plates 240 :and the upper ends of the stub plates are connected to chains 241, 242. A spacer bar 243 passes through mutually opposite links in chains 241, 242, and divides the chains into lower Vvertical portions and upper inwardly converging portions. Pairs of washers 244, 245 prevent sideways slippage of the chains along the bar. In this instance, inner washers 244 are welded to the spacer bar yand outer washers 245 are maintained in place by nuts 246 threaded on the projecting ends 247 of the spacer bar.

The use and operation of the invention is as follows:

The return reach of a conveyor belt may detrain for a number of reasons. The roller which supports the belt may be skewed with respect to the direction of belt travel for example. Whatever the cause, belt drift or detraining may be overcome by freely swingably suspending the return roller so ythat it may cant in response to misalignment of the belt. In 'FIGURE 4, for example, the belt is shown in a detrained condition to the right as it passes over the return roller 224, and the roller is canted forwardly to the right in a training direction. The force exerted by the belt on the roller is generally directed perpendicular to the longitudinal axis of the roller as indicated at 236a. As the belt moves to the right, the orce exerted on the roller willcant the right end of the roller -forward in the direction of belt travel and will swing the left end rearwardly. Since the training effect .imparted to the belt is exerted in a direction perpendicular to the longitudinal axis of the roller, the belt will be urged to the left. As the belt moves to the lett, the roller will swing back to an equilibrium position illustrated by the normally positioned longitudinal axis 237. The swinging of the return roller in the plane parallel to the plane of the belt is termed canting for convenience.

The angle formed by the connector device between the return roller and the ilexible strand is an important factor in maintaining a freely cantable condition of the roller. When the connector devices extend vertically downwardly from the llexible strands .to the ends of the rollers, there is no resistance to drift of the belt other than the vforce required to lift the roller and belt to a new height. When the connector devices converge upwardly toward :the strands, the total force resisting belt drift consists of the force required to lift the roller and belt to a new height plus a horizontally directed pendulum force. To obtain upward convergence of the connector devices, it is common practice to place shaft extensions on the dead shaft 225 of the roller which intersect at a point 248 in FIGURE 2. These shaft extensions increase the cost of the roller assembly and increase its length which is `a disadvantage in mines with small edge clearance.

The upwardly extending straps 22S, 229 retain the desirable features of the upwardly convergent connector devices while eliminating shaft extensions. In FIGURE 2 the connector devices are composed of chains 231, 232 connected at their lower ends to rigid metal straps or end plates 228, 229 which receive the dead shaft 225 in hubs 226 at there lower ends. The straps are non-flexible with respect to the shaft 225 and the chains are bodily ilexible. Thus the roller may cant to and fro in a plane parallel to the belt because of the swivel connection between the tlexible strands and straps. It will be understood that other connectors could be substituted for the chains. It is important however that the inwardly converg'ng member :be so connected to the strand Iconnectors 234- and to the upper ends of the straps as to permit swinging movement of the connectors both transversely to and parallel with the longitudinal axis of the conveyors.

In FIGURE 5 spacer bar 243 prevents the chains 241, 242 from collapsing inwandly. One advantage of this arrangement is that composite connector devices such as the strap and chain arrangement of FIGURE 2 may be avoided if misalignment is not too severe. If misalignment becomes a problem, the mine owner can merely place the spacer bar 243 between the connecting chains intermediate the ends of the roller and the exible strand without stopping the conveyor and achieve the advantages of shaft extensions.

Although chains have been illustrated in each embodiment for joining the ilexible strands to the lower member comprising the connector devices, it is possible to use a bodily rigid member such as a shaft. Itis only essential that the member be connected at its ends so as to permit canting and tilting movement of the `roller assembly, as by la universal type joint. Lt is likewise feasible in any particular conveyor installation to install the present invention intermittently as well as sequentially depending on the amount of detraining.

The foregoing description is illustrative only and not definitive. Accordingly, the invention should not be limited except by the scope of the following appended claim.

I claim:

A return roller assembly for training the return reach of a belt in a belt conveyor in response to passage of the return reach thereover in a detrained condition, said conveyor being of the type having return roller assemblies supporting the return reach of the belt from elevated support means, and troughing idler assemblies supporting the conveying reach of the belt,

said return roller assembly being elfective to train the return reach irrespective of, rstly, the direction of movement of the return reach, and secondly, the behavior of the conveying reach of the belt,

said return roller assembly including, in combination,

a return roller, and

a pair of freely hanging, elongated connector assemblies for suspending the return roller from the elevated support means in a @generally horizontal position at a location remote from the nearest troughing idler assembly,

said return roller having a length substantially equal to the ydistance between the points of connection of the elongated connector 4assemblies to the elevated support means,

the freely hanging, elongated connector assemblies enabling the end portions tof the return roller to swing to and fro -in the same or opposite directions in response .to the passage of the return reach of the belt over the return roller in a detrained condition,

said directions being generally parallel to the conveying course,

said freely hanging, elongated connector assemblies,

|when not under the influence of the detrained behavior of the belt passing thereover being oriented in a generally vertical plane transverse to the conveyor course,

each elongated connector assembly comprising a rigid connector extending longitudinally, outwardly and thence vertically upwardly from each end portion of Vthe return roller, the angle between the rigid connector and return roller axis being constant in all positions of the return roller, 5

a link assembly Iexibly connecting the upper end of each rigid connector to an associated elevated support means,

each -link assembly converging lupwardly from the upper end or' its associated rigid connector to its associated 10 elevated support means.

References Cited in the le of this patent UNTED STATES PATENTS Klein Oct. 12,

Craggs et al. Dec. 4,

Lo Presti May 5,

Stinson Sept. 15,

FOREIGN PATENTS Germany June 27,

Germany Sept. 3, 

